Weed management in sweet corn and other rotational crops (2008)

Report to the Oregon Processed Vegetable Commission

Ed Peachey and Alysia Greco
OSU Dept. of Horticulture

Chris Boerboom, University O Wisconsin, Madison, WI
Marty Williams, USDA, Champaign-Urbana, Ill
Rick Boydston, USDA, Prosser, WA
John Orr, AMVAC, Boise, ID
Norm McKinley, DuPont, Salem, OR


Both Impact and Laudis are effective grass killers. The weed control spectrum of these herbicides was enhanced by the addition of atrazine. Both are weak on purslane. The data from the Stayton I experiment with Coho sweet corn suggest that corn yield may have been reduced by as much as 14% by tankmixing and applying Impact and Laudis with either Outlook or Dual Magnum herbicides at V 5-6. Low rates of atrazine likely improve the efficacy of HPPD inhibit herbicides, but may not reduce competition enough to improve yield, even (especially) at extremely weedy sites. Accent Q is less likely to cause injury to corn than Accent (without a safener). The new PPO herbicide from BASF (Kixor) caused significant injury to corn when applied PRE and injury was not consistent among the 40 varieties tested. Two years of testing indicate that the risk of Impact carryover is low, but that 2X rates of Impact may reduce table beet yield, growth of fall planted mustard, and influence snap bean grade 9 months after application. Seed predation in several grower fields followed carabid beetle activity during the summer. Wild proso millet emergence declined with increasing activity-density in research farm plots. A few puncturevine seeds survived 196 F for 1 hour.